無線感測網路中改善資訊融合精確度之兩種最終決策機制

Two Final Decision Schemes for Improving the Accuracy of Decision Fusion in Wireless Sensor Networks

陳侶親(Leu-Chin Chen)

指導教授 ： 杜迪榕

共同指導教授 ： 王藏億

國立暨南國際大學/科技學院/資訊工程學系/碩士(2009年)

https://doi.org/10.6837/NCNU.2009.00097

摘要

近年來的科技促使無線通訊、資料運算和感應器變得日新月異，因此這套聰明的無線感測網路系統被發展用來監測我們有興趣的環境當中。然而，被感測環境當中的雜訊會影響到該區域決策的結果，除此之外，這些被雜訊影響的區域決策也會造成最終決策結果的不可靠。本研究提出使用在資訊融合節點的兩個新穎並且有效率的方法來得到更低錯誤率的最終決策機制。其中一個機制是使用佇列做出最終決策，另一個機制則是使用飽和計數器來做最終決策，這兩種方法都可以有效率地降低最終決策的錯誤率。根據實驗結果，佇列的長度和飽和計數器可計數的最大值都會影響到該監測系統的效能，所以如何決定出最好的佇列長度和飽和計數器的可計數的最大值是本研究的目標。然而，實際上這兩種提出的機制隨著佇列長度越大或是飽和計數器大小增大皆會有偵測延遲的產生，因此可以得到必須要在降低錯誤率和將低延遲之間做出一個抉擇。很不幸的，要使用數學方法分析佇列機制的最終決策錯誤率是很困難的。在本研究，我們只用數學分析討論飽和計數器機制的最終決策錯誤率。根據實驗的結果顯示所建議計數器的最大值可以在不同的環境場景底下得到最佳的偵測效能。此外，本機制也比傳統上著名的用多數決最終決策機制方法還要好。

關鍵字

無線感測網路 ； 決策融合 ； 佇列 ； 飽和計數器 ； 最終決策 ； 錯誤率

並列摘要

Since the recent electronic technologies develop the wireless communication, computation and sensing devices becoming more advance, a smart system, wireless sensor network (WSN), is proposed to monitor a region of interest. However, the noise in the environment may affect the local outcomes after detection. Moreover, these results of affected local detection cause a final decision being unreliable. This work addresses two new approaches to get a lower final decision error rate on the fusion center effectively. One of the proposed schemes uses a queue to make the final decision in the interested region, and the other scheme adopts a saturation counter to do the same thing. Continuously, the both schemes can degrade the decision error efficiently. The experimental results show that the queue length and maximum counter value can obviously affect the performance. Therefore, the goal of this work is to determine the best queue length and maximum counter value. The truth remains, however, that both queue and decision counter also bring some detection delay which is according to the queue length or maximum counter value adopted. Obviously a trade-off is between error rate and detection delay. Unfortunately, the error rate of the queue scheme is hard to analyze mathematically. This work only analyzes the error rate of the saturation counter scheme. The experimental results demonstrate that the suggested maximum counter value can get the best performance in different scenarios. Moreover, the scheme is superior to the conventional fusion scheme, which uses the well-known k-out-of-N final decision rule directly.

並列關鍵字

wireless sensor networks ； decision fusion ； queue ； saturation counter ； final decision ； error rate

參考文獻

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